An apparatus and method measures and analyzes DC current passing through a substantially insulating member or dielectric material that is electrically connected to, or otherwise conductive, between an energized DC electrical transmission line and an Earth potential or ground. An apparatus may utilize a DC current measuring device, a DC voltage level selection switch, a DC display, a graphical display of momentary leakage current, and an audio speaker. A process may entail extending a substantially insulating member or dielectric material between an energized DC electrical transmission line and an Earth potential, detecting a DC momentary leakage current, using a DC momentary leakage current meter to measure DC current through the member or material, and a computer to analyze and compare the DC current, and deliver results or a warning that the DC current has reached a threshold value.